Potential economic viability of growing industrial hemp (Cannabis sativa) at the Taupo, New Zealand effluent disposal site

A cost-benefit analysis of growing industrial hemp (Cannabis sativa) at the Taupo District Council effluent disposal site, Taupo, New Zealand was compared to the actual costs and returns of the current operation of growing grass cut and sold as silage. The lack of agronomic data from hemp grown in New Zealand meant that major assumptions were made. One assumption was that hemp can be regrown from stubble for a second cut, as long as the first cut takes place before the onset of reproductive growth. If two cuts can be made in a season from a single sowing, hemp might be grown at similar economic returns to the silage operation if fibre prices are NZ$100-160/t. If only a single cut is possible, fibre prices need to be between NZ$220 and NZ$330/t. Prices for both situations are well below the price of NZ$600/t paid for imported fibre from China although the latter price includes the cost of retting. The relative low fibre prices required for achieving the status quo economically in relation to what a manufacturer is prepared to pay for hemp fibre indicates that growing industrial hemp in New Zealand could be economically viable. However, there is a need for field trials to establish hemp yields and to develop agronomic protocols in New Zealand.